Method and apparatus fob making



D. AND LLOW R June 8, 1943. G REMPEL v METHOD APPARATUS FOR MAKING H0 UBBER ARTICLES Filed April 17. 1940 r 3 Sheets-Sheet l INVENTOR.

D IE7'F?ICH G. REMPEL June 8, 1943.

D G REMPEL HOLLOW RUBBER ARTICLES Filed April 17, 1940 METHOD Ami ARPARATUS FOR MAKING.

5 Sheets-Sheet 2 INVENTOR.

D/ETRICH 6. FEMPEL.

, June 8, 943. REMPEL 2,321,319

METHOD AP ATUS FOR ING HOLLOW RU R ARTICL Filed April 17, 1940 .3 Sheets-Sheet 3 Q i ZW F6. 3

j 33 36 32 Dun-man- 6; PEN/=54. v

BY A174 I I 1 t INVENTOR.

Patented June 8, 1943 4 Mn'rnop APPARATUS FOR MAKING noniow nunnnn An'rrcms Dietrich G. Itempel, Barberton, Ohio, asslgnor to The Sun Rubber Company, Barberton, Ohio, a

corporation of Ohio Application April 17, 1940, Serial No. 330,101

11 Claims. (01. 18-19) This invention relates to method and apparatus for manufacturing hollow rubber articles, 1siiligch as hollow rubber character dolls, or the Heretofore, such hollow rubber articles have been manufactured by providing a preformed biscuit comprising two sheets of raw rubber formed roughly in the shape of an article to be manufactured with the marginal edges of the sheets adhering and a pellet of volatile material, such as an ammonia compound, being incorporated within the biscuit; placing this biscuit in a sectional mold; heating the mold to vulcanizing temperature to volatilize the pellet and increase the pressure in the biscuit, thereby expanding the walls-of the biscuit against the cavity surfaces of the mold. This curing process,

however, required a considerable period of time because the mold had to cool to reduce the pressure in the article before the mold could safely be opened.

An object of the invention is to P ovide a method and apparatus of the character described in which the internal pressure of the article may be released after the vulcanizing period to permit the mold to be safely opened,

Figure 5 is a fragmentary cross-section through one of the sectional mold units inthe press closed position thereof and illustrating a perforating device in association with the lower section ofsaid mold unit. I

Figure 6 is an enlarged cross-section through one of the article perforating devices after inwithout waiting for the mold or the article to cool, thereby materially increasing the production rate of such articles, and consequently reducing the production costs thereof.

Another object of the invention is to provide apparatus of the character described having improved means operable at will, while the vulcanizing mold is closed for the vulcanizing cycle, for accurately perforating hollow rubber articles in the mold.

These and other objects of the invention will be manifest from the following brief description and the accompanying drawings. I

Of the accompanying drawings: 4

Figure 1 is a side elevation, partly broken away, of a vulcanizing press having the apparatus embodying the invention incorporated therein, the press being shown in open position.

Figure 2 is a fragmentary front elevation,

ternal pressure has been applied within an article under heat of vulcanization in the mold unit.

Figure 7 is a cross-section similar. to Figure 6, illustrating the manner in which the perforation is cut in an article by the rotary cutter.

Figures 8, 9' and 10 are cross-sections taken substantially on lines 8-8, 89, Iii-Iii, respectively, of Fi ure 6.

Figure 11 is a cross-section taken on line.

ll-li of Figure 7.

Referring to thedrawings, the numeral l5 designates a vulcanizing press of known type, comprising a fixed lower platen i6 and a relatively movable upper-platen II, the press supporting and operating mechanism being indicated generally at l8. The platens i6 and I! may be heated to vulcanizing temperature by suitable means (not shown).

Removably secured to, platens i6 and I! are plates l9 and 20, respectively, to which may be secured by means of screws 23, 23, lower and upper registering sections 2|, 2| and 22, 22, re-

spectively, of a plurality of cavity mold units 23, 23 (see Figure 5). The press mechanism i8 is operable to move the upper sections 22 on f platen ll toward and from registry with the lower sections 2| on platen l6. Removably and plates 24, 25 for adjusting the sections relative partly broken away and in section, taken substantialiy at line 22 of Figure 1, and illustrating the improved article perforating mechanism in association with the lower mold sections in the press.

Figure 3 is a plan view, partly broken away 7 and in section, of the portion of the apparatus shown in Fi ure 2. I v

Figure 4 is a. fragmentary end view thereof,

as viewed from the side of the press.

to the supporting plates i9 and 20 thereof.

Referring to Figures 5 toll, a sleeve 25 may be fixed in the bottom of each lower section 21, the upper part of said sleeve being internally threaded at 26 for receiving an enlarged threaded portion 21 of a rotary cutter 28, the

' A (see Figure 7).

so that rubber will not enter the same to clog.

aperture 3| in the article. A bar or key may be firmly engaged between plate I9 and lower platen l9, as shown, to engage in a cut-out portion 25 in the lower end of sleeve 25, the inner edge of the bar engaging fiat portions 25, formed on the sleeve by said cut-out portion, to prevent rotation ofthe sleeve relative to the mold section 2|.

For rotating the cutter 28 and simultaneously shifting the same to cut the aperture 3| in the wall of the article, the lower end of the cutter may have a pinion 32 integral thereon, engaging a rack 33 slidably mounted between the lower plate l9 and plates'24 of lower mold sections 2|, one of these racks 33 being provided in association with each row R of said sections and engaging pinions 32, 32, on the rotary cutters in each mold section 2|. The arrangement as shown is such that forward movement'of racks 33 relatively of the press will engage pinions 32 to rotate cutter 29, and with this rotation the threaded portions 21 of the cutter will engage the threads 25 of sleeve 25 to shift the cutter in bushing 39, upwardly from the position thereof shown in Figure 6 to the position shown in Figure 7. Thus the cutting edge of rotating stem 29 in moving to projecting relation through the wall of the article A will cut a plug P from said wall, this plug engaging in the seat 29 at the inner end of the stem to be lifted from the aperture 3 I. as shown in Figure 7.

The bore 35 of stem 29 may be extended through the entire cutter to receive a pin 36. the

inner end of which extends: to adjacent the cavity surface of the mold section 2|, and the other end of the pin having a head 31 engaging in a counter-sunk hole in a disc 39, this disc being engaged between a shoulder portion 39 on sleeve 25 and the face of lower platen IS. The disc 38 is adapted to retain the pin 31 in fixed position relative to the sliding movement of cutter 28.

The stem 29 may be provided with apertures 40, 43 communicating the bore 35 thereof with the interior of article A in the mold when the stem is in the projecting relation shown in Figure '7. The apertures 40 are located to be beneath the plug P received in the seat 29' in said projecting position, but may be closed off between the surfaces of bushing and pin 36 in the withdrawn position of the cutter shown in Figure 6. The pin 38 may be provided with a longitudinally extending groove 4|, communicating the upper portion of bore with the exterior, for relieving the internal pressure of the article when desired upon cutting the aperture 3| in the article Groove 4| is relatively small it during the vulcanizing cycle.

The arrangement of the rotary cutters and the associated parts thereof, as best viewed in Figures 6 to 10, is such that by removing plate l9 with the lower mold sections 2| thereon from the lower platen l5, and by removing racks 33, the various parn of each unit including sleeve 25, cutter 29, bushing 39, pin 35, disc 38, and bars 25, etc., may readily be removed, as for cleaning the same.

As best shown in Figures 1, 2, 3 and 4, the front ends of the racks 33, cooperating with the respective rows R of mold sections, may be secured to a laterally extending cross-bar '42. At the center of the cross-bar may be an outwardly extending U-shaped portion 43, to which is pivotally connected 8. bifurcated head 44 on the end of piston-rod 45 of a-cylinder 45, which is secured to relatively fixed portions of the press structure.

Piping 61, 41 connects cylinder 46 to a suitable source of fluid-pressure supply, the cylinder being operable at will through a valve (not shown), to shift the racks 33 forwardly and rearwardly as indicated in full and chain-dotted lines in Figure 3, to move cutter 28 toward and from the inwardly projecting positions thereof shown in Figure 7.

In the operation of the apparatus, which in the present case is adapted for vulcanizing blown rubber articles, such as hollow rubber character dolls, or the like, uncured articles A are first placed in the cavities of the lower mold sections 2|, these articles having been preformed in known manner, as by adhering two sheets of raw rubber to form a biscuit roughly in the shape of the finished article to be manufactured, and with a pellet of volatile materialwithin the biscuits, as previously described. The press is next closed with the lower and upper mold sections 2| and 22 in registry, as illustrated in Figure 5, and the platens are heated to vulcanizing'temperature. which causes the pellets in the article biscuits to expand the walls thereof against the surfaces of the mold cavities. This expansion urges a portion of the wall of each article against the partially projecting ends of stems 29-of the respective cutters 28, partially to cut apertures 3| in the articles.

At the end of the vulcanizing cycle, before the press is opened. cylinder 46 is actuated to move the racks 33 forwardly in unison, from the fullline positions to the chain-dotted positions shown in Figure 3. With this forward movement, the racks 33 engaging the pinions 32 of cutters 28 cause the cutters to rotate, whereby rotational movement is imparted to the theaded portions 21 of the cutters in the threaded portions 26 of the relatively fixed sleeves 25, to cause the rotating cutters to move inwardly of the mold to project the stems 29 through the wall of the articles A to form apertures 3| therein. The plugs P from the apertures are engaged in the seats 29 at the ends of stems 29 and lifted free of the apertures. The inward rotational movement of the cutters 28 cutting through the hot rubber of the articles forms apertures 3| as accurately as could be drilled or punched against a solid surface.

Substantially simultaneously with inward movement of stems 29 the fiuid pressure within the articles A is vented through the apertures 40 in the stems 29, and thence vented through the grooves 4| in the pins 4| to the atmosphere.

- This allows the vulcanized articles A in the molds 23 to cool rapidly, the heat to the platens l6 and I1 preferably having been shut off, and permits opening of the press and removal of the articles therefrom substantially at the end of the vulcanizing period, thereby eliminating the usual procedure of waiting for the molds to cool before opening the press. The apertures 3| in the finished articles A may be utilized for receiving noisemakers of known type.

As soon as the vulcanized articles A are all removed from the lower mold sections 2|, the cylinder 45 may be operated to move the cross-bar 42 inwardly from the chain-dotted to the fullline positions shown in Figure 3, thereby withdrawing the rotary cutters 29 from the fully projecting positions thereof shown in Figure 7 to the partially projecting position shown in Figure 6, when the procedure described may be repeated 4 for vulcanizing another batch of articles.

Thus has been provided improved mechanism mounted in said mold, means operable at will 10 simultaneously to shift said cutter to project through the wall of an article in the mold against the intemai pressure thereof, and thereby cutting an aperture in said wail, said cutter having a seat thereon for receiving the plug cut from said wall, said cutter having a vent beneath said seat adapted to relieve the internal pressure in said article when the cutter is in said projecting position.

DIE'IRICH G. 

